The present invention relates to a lightguide connector joint for an endoscopic system, by which a lightguide connector of an endoscope is connected to a light source apparatus.
In general, an endoscope is equipped with an illumination light guide an illumination light entrance end face of which is disposed at a distal end face of a lightguide connector. A connector receptacle to which the lightguide connector is to be connected is provided in a light source apparatus having a built-in light source. When the lightguide connector is connected to the connector receptacle, the entrance end face of the lightguide is situated in a specified position near a position at which the rays of illuminating light radiated from the light source are converged.
Various endoscopes of the above-noted design are available depending on respective purposes and intended uses, and an operator can select one or ones from the various endoscopes in combination with a single light source apparatus to constitutes a desired endoscopic system. In the endoscopic system, a selected one of the endoscopes is connected to the light source apparatus depending on a specific purpose or use. However, the thickness of an endoscope""s illuminating lightguide (or the number of optical fibers in it) varies with the endoscope model or type.
Some combinations are appropriate in that when the endoscope""s lightguide connector is connected to the connector receptacle in the light source apparatus, the illuminating light is incident on the entrance end face of the lightguide to give neither surplus nor deficiency.
However, in a model of endoscope having a smaller entrance end face of lightguide than the appropriate model, a portion of the illuminating light fails to be incident on the lightguide and the efficiency of illumination is reduced. In other words, sufficiently bright illuminating light cannot be obtained even if a high-intensity light source is used.
Conversely, in a model of endoscope having a thicker entrance end face of lightguide than the appropriate model, a relatively small amount of illuminating light is incident in those areas of the lightguide which are far from the center and the object is illuminated unevenly.
The present invention has been accomplished under these circumstances and has as an object providing a lightguide connector joint for an endoscopic system which is compatible with various endoscope models using lightguides with different thickness of entrance end face and which ensures that the rays of illuminating light radiated from a light source are incident on the lightguide to cause neither surplus nor deficiency, thereby achieving satisfactory illumination with high efficiency.
The stated object of the invention can be attained by a lightguide connector joint for an endoscopic system in which the entrance end face of an endoscope""s illuminating lightguide is disposed at the distal end face of a lightguide connector, and a connector receptacle to which said lightguide connector is to be connected is provided in a light source apparatus having a built-in light source. When said lightguide connector is connected to said connector receptacle, the entrance end face of said lightguide is situated near a position in which the rays of illuminating light radiated from said light source are converged. In the light guide connector joint, the shape and dimensions of said lightguide connector are determined in accordance with the size of the entrance end face of said lightguide such that the smaller the size of said entrance end face, the closer to the converging position of said rays of illuminating light is the position of said entrance end face that is established when said lightguide connector is connected to said connector receptacle.
If desired, said connector receptacle may be shaped in the form of a tapered hole that progressively decreases in diameter in a direction toward said light source whereas the tip portion of said lightguide connector is shaped in the from of a tapered rod that fits into said connector receptacle.
Another embodiment is such that when said lightguide connector is connected to said connector receptacle, a stopper formed on said lightguide connector contacts a reference positron formed on said connector receptacle side and that the distance from said position of contact to the entrance end face of said lightguide is determined in accordance with the size of said entrance end face.
In yet another embodiment, a ventilation window for cooling the distal end portion of said lightguide connector is provided in a lens unit incorporating a lens for converging the rays of illuminating light radiated from said light source. If desired, a cooling fan may be provided in the ventilation window.
The present disclosure relates to the subject matter contained in Japanese patent application No. Hei. 10-201649 (filed on Jul. 16, 1998), which is expressly incorporated herein by reference in its entirety.